no population term should have a has_penetrance relation - CHECK FAILURE:  expected 0 but got 3
name	uniquename	cvterm_name	uniquename
  [null]	PomBase-genotype-108121	increased vegetative cell population binucleate index [has_penetrance] complete	PMID:11460168
  [null]	8ca59104c61e0b02-genotype-7	increased vegetative cell population binucleate index [has_penetrance] complete	PMID:11460168
  [null]	PomBase-genotype-1432	increased vegetative cell population binucleate index [has_penetrance] complete	PMID:11460168